1. Field of the Invention
This invention relates to an arrangement of nautical charts on a single sheet of flexible material or paper that is suitable for piloting. In particular, this invention relates to an arrangement of nautical charts on a single sheet of, desirably, waterproof paper having at least one small scale chart and a plurality of large scale charts whereby the combination of all the charts represents a substantially continuous shoreline.
2. Description of the Prior Art
Piloting is commonly defined as navigating a craft in optical or electronic sight of land. Electronic sight can include the use of RADAR equipment to identify objects on the shore. The position of the craft in the water is calculated by a navigational method known as triangulation. Triangulation consists of obtaining a magnetic compas or gyro compass bearing of an optical or electronic line of sight from the small craft to two or more specific landmarks on the shore. The landmarks are identified on a chart of the shoreline and lines are drawn on the chart from the representations of the objects at angles corresponding to the angles of the lines of sight. The point of intersection of the lines drawn on the chart is the navigational position or "fix" of the small craft. Explanations of piloting and navigation can be found in many reference texts including Piloting and Dead Reckoning by Shufeldt and Dunlap, published by the Naval Institute Press, 1970.
Piloting charts present sufficient detail of a shoreline to represent specific landmarks that can be recognized from a vessel on the water and in sight of the shoreline depicted by the chart. Charts of harbors or inlets are usually rendered in 1:40,000 scale or less frequently in 1:10,000 scale. These scales represent a small nautical and geographic area and are termed large scale charts. Coastwise charts, embracing stretches of shoreline that contain several harbors often have a 1:80,000 scale. This scale represents a relatively large nautical or geographical area and is termed a small scale chart. Small scale charts bear the name of the area that they depict or cover such as "Tampa Bay" or Long Island Sound-Eastern Part.
Open ocean navigational charts are much smaller in scale than are charts used for piloting. Open ocean navigational charts depict large areas of ocean and typically contain no shoreline detail. Open ocean navigational charts have a 1:1,000,000 scale or larger.
As can be appreciated a small scale chart is one in which features are presented in smaller size and less detail than on a large scale chart. The demarcations between large scale and small scale charts is relative. For this reason the descriptions above are provided as a general guide to the terms used in the art.
Special folio-style charts, known as Small Craft Charts, are published for areas that have a significant amount of small craft traffic. These charts have several fold-out segments stapled together in protective covers along with tidal and harbor facility information. These charts are considered easier to use in a confined cockpit of a skiff or daysailer than are the large format navigational charts used on larger vessels. Small Craft Charts usually represent a shoreline in a 1:40,000 scale. The user of these charts can obtain navigational information by flipping through the charts printed on small sheets of paper and attached together in a book format.
The user of Small Craft Charts cannot obtain a "total picture" of all the shoreline represented all by the charts without disassembling the charts from one another and fitting them together. A book format as used in Small Craft Charts does not lend itself to navigational plotting because sight lines from a landmark often cross over onto another chart. Additionally, Small Craft Charts often do not contain sufficient number of large scale charts of restricted navigational waters to provide adequate detail for the navigator of these waters. This lack of large scale charts requires the small craft navigator to have separate large scale charts on board his vessel.
Desirable piloting charts are of a sufficient size to permit the navigator to draw sight lines or "readings" on the chart. Conventional piloting charts available from the U.S. National Oceanic and Atmospheric Administration (NOAA) are typically printed on only one side of a large sheet of paper. Paper sizes for NOAA charts are often about three feet in height and three and one-half to four feet in width. NOAA charts of this size frequently contain only one chart of a single scale to depict the shoreline representation presented by the chart. Piloting charts of this nature are too large and cumbersome for use on a small craft that has no chart table. Piloting charts, because of their size, must often be folded in order to be handled on a small craft. When a chart is folded the navigator of the craft loses the benefit of quick reference to all the information presented on the chart. Additionally, charts are frequently carried on board small craft in transparent plastic pouches or "chart pockets". If the chart is carried in a waterproof chart pocket, folding the chart by removing the chart from the pocket exposes the chart to the elements. If the chart is folded along with the chart pocket, the chart pocket can be permanently creased or destroyed.
Examples of navigational charts including small craft charts are found in patents, technical literature, and actual commercially available charts. The following specific examples are provided.
The Miami to Card Sound marine chart by U.S. Master.RTM. published by Cartographic Corporation Box 88, Manchester, Mass. 01944, is an example of a waterproof chart depicting two small scale charts and a number of related large scale charts that define only very narrow sections of shoreline. The large scale charts taken in combination do not represent a substantially continuous section of shoreline. Insert Number 1 of Miami Beach illustrates a seven mile stretch of a Miami channel. This channel is presented on such a small section of the overall chart representation that size constraints do not provide enough surface area for the navigator to chart repeated fixes when navigating the channel. The small scale charts do not depict sufficient landmarks to facilitate the navigator's plotting of his position. Under foul weather conditions an inadequate number of landmarks depicted on a piloting chart render that chart useless because of the restricted visability.
U.S. Pat. No. 1,429,285 to Harriman discloses a waterway chart. The waterway chart graphically expresses facts concerning waterways and other bodies of water and their relation to commercial, industrial and recreational uses. Selective facts concerning the seacoast, the rivers entering the sea along this seacoast, and the tributaries and lakes connected to these rivers are shown. This chart is not intended or suitable for piloting small craft. The length of sea coast illustrated in this waterway chart is printed on sizes or paper having insufficient area to draw repeated fixes when navigating the coastline. There are no distinct landmarks depicted on the coastline of this chart.
The Galveston Bay fishing map published by Hooksetter Fishing Maps, P.O. Box 7330, Bay Plaza Station, Baytown, Tex. 77520, is an example of a waterproof chart for small craft. This fishing chart depicts a number of large scale charts in its inserts. The combined charts are arranged on one sheet of paper in a manner suitable for use while fishing in specific areas of the bay. The large scale charts do not depict a substantially continuous section of shoreline in a suitable manner to readily facilitate navigating from the areas depicted by one large scale chart to an area depicted by another large scale chart. Small craft navigating between the different areas depicted by the large scale charts is made cumbersome by the lack of a substantially continuous representation of shoreline in the large scale charts.
Cartographers, when producing maps, encounter difficulties similar to those described above when presenting detailed map information on large scale maps in conjunction with general information presented in a small scale map. A map is a representation of a land surface. Road maps are generally depicted in the form or a large folded sheets of paper. Small scale road maps are generally not detailed enought to provide a guide through cities or towns contained in the territory covered by the map. Cartographers have attempted to solve these problems in numerous ways.
U.S. Pat. No. 1,364,239 to Bloomfield discloses a scroll map. The map is arranged in a form such that the map can be compactly arranged in a small space convenient for ready reference. The map represents a given geographical area divided into a number of parallel sections. The parallel sections are arranged in a parallel single line on a single strip of paper that is mounted at each end on rollers. The map illustrates a given area as well as enlargements of certain portions of the geographical areas. The map sections are arranged in an order such that a traveler can determine his position while travelling to a given destination. The user must shift the strip map from one section to another to determine his position on the map. A number of sections representing a substantially continuous road are not simultaneously viewable. A chart having similar construction is not suitable for piloting small craft because of the cumbersome nature of a scroll format and the inability of the navigator to plot on portions of the scroll without the scrolls unrolling as his small craft is tossed about by waves.
U.S. Pat. No. 1,537,634 to Watson discloses a road map. Map sections are provided in sheets which can be attached in a book format. One using the road map can organize a tour by placing map section sheets in the book in a sequence corresponding to the chosen route. The book can then be conveniently handled by the automobile tourist while driving. The map sections in the book are not simultaneously viewable. A chart having similar construction is not suitable for piloting small craft for the same reasons as detailed above for the Small Craft Charts.
The industry lacks a chart for use with small craft piloting and navigation that illustrates on a single sheet of paper a substantially continuous shoreline. The industry lacks charts suitable for piloting that provide the small craft navigator with an acceptable arrangement of chart information on a single sheet of flexible material or paper for quick and easy use when navigating near a shoreline.